HOMEWORK 3 - SOLUTIONS
2.21. (a) Silicon is doped with ND=5 1015cm-3. Find n0 and p0 , and locate the Fermi
level. Draw the energy band diagram.
The material will be n-type. Since the number of donors is much greater than the
intrinsic concentration, and
MIDTERM 2
EE 432
Fall 2011
Pledge: No aid given, received, nor observed.
Tintin
Name:
Signature: Milou
Question # 1 / 6 FET Types (12 points)
(a)Indicate below which device is a (J)FET, (MES)FET, (H)EMT, (MOS)FET (4 points).
(b)Circle the channel in the d
HOMEWORK 4 - SOLUTIONS
CHAPTER 4
4.7. Draw the energy band diagram for GaAs that is doped such that EC-Ef=0.2+
(0.8 eV/ m)x for 0<x<0.5 m.
a) Find the effective electric field for electrons
*
The electric field is E e =
1 dEC
1
0.4eV (1.6 1019 J / eV )
=
Homework 6 Solutions
7.3. For the transistor of Figure P7.1, by how much should the gate voltage be
changed to produce inversion? Threshold? Assume half the applied voltage appears
across the oxide and half across the semiconductor. If the device in the f
ECE 432
Spring Quarter 2012
HOMEWORK ASSIGNMENT NO. 5
DUE : Friday, May 4, 2012
1. What is the conductivity of a piece of Ge (ni = 2.5x1013 cm-3) doped with 5x1013
cm-3 donors and 2.5x1013 cm-3 acceptors? (Dn = 100 cm2/s, Dp = 50 cm2/s). If the
electron a
ECE 432
HOMEWORK ASSIGNMENT NO. 4
Spring 2012
DUE : Friday, April 27,2012
Please complete the following problems:
1.
Modify the xpo and xno expressions in Eq. (5-23) for the case of reverse bias
Vr> V0 and show that the peak electric field 0 is dominated
ECE 432 Spring Quarter
HOMEWORK ASSIGNMENT #6
DUE : Wednesday, May 16, 2012
Please complete the following exercises:
1.
A Si solar cell 2 cm x 2 cm with Ith = 32 nA has an optical
generation rate of 1018 EHP/cm3s within Lp = Ln = 2 m of the junction.
If t
ECE 432 Spring 2012
HOMEWORK ASSIGNMENT 2
DUE: Wednesday, April 11, 2012
Please complete the following exercises:
1.
A Si sample with Nd = 1015 cm-3 donors is uniformly optically excited at room temperature
such that 1019 cm-3 electron-hole pairs are gene
ECE 432 Spring Quarter 2010
HOMEWORK ASSIGNMENT NO. 1
Please complete the following exercises by Wednesday, April 4, 2012. Due in class.
1. Why is ZnS a more useful phosphor for television screens than CdSe? If the band
gap of the ternary alloy GaAsP vari
ECE 432 Spring 2012
HOMEWORK ASSIGNMENT NO. 3
DUE : Wednesday, April 18, 2012
1.
An abrupt Si p-n junction has Na = 5 x 1017 cm-3 on the p side and Nd = 5 x 1016
cm-3 on the n side. At 300 K, (a) calculate the contact potential of the Si device,
(b) calcu
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ECE432
Physics of Semiconductor Devices
Instructor:
Patrick Roblin
Department of Electrical & Computer Engineering
The Ohio State University
Columbus, OH 43210
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ECE432
Excess Carriers in Semiconductors
Chapter 2
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Lecture # 4
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Carriers Concentrations in
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ECE432
Junctions
Chapter 3
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Lecture # 7
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Introduction
I
P
N
V
Applications:
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recti cation,
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EE432
Field-E ect Transistors
Chapter 4
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Lecture # 13
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Various Types of FETs
a) Junction FE
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EE432
Bipolar Junction Transistors
Chapter 5
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Lecture # 17
Introduction
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BJT Symbols
P
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Optoelectronic Devices
Chapter 6
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Lecture # 20
Photo-diode
Solar cell
LED
Laser
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Phot
Homework 7 Solutions
7.12. An NFET is made with tox=4 nm, L=1m, W=10 m, VT=1V, and
lf = 500 cm2 / V s .
If the simple model is used, what should the width of the PFET be to get the
same characteristics (apart from polarity). Let the low field mobility for
Homework 8 Solutions
9.3. Draw the energy band diagram for a pnp transistor at equilibrium and
under forward active bias.
The drawing should reflect the relative dopings as well:
p+
emitter
-W E
n
base
p
collector
p+
collector
WBM
x
EC
EC
E ,E
fV
E ,E
fV